Motor-controller.



E. B. H. TOWER, JR.

MOTUR GONTRO'JLER.

APPLICATION FILED NOV. 26. 1909 Patented Apr. 29, 1913.

2 SHEETS-SHEET 1.

E. B. H. TOWER, JR. MOTOR CONTROLLER.

APPLICATION 1111,21) NOV. 26, 1909.

Patented Apr. 29, 1913.

2 SHEETS-SHEET 2.

UNITED STATES PATENT OFFICE.

EDWIN B. H. TOWER, JR., OF MILWAUKEE, WISCONSIN, ASSIGNOR TO THE CUTLER-HAMMER.MFG. 00., OF MILWAUKEE,

WISCONSIN, A CORPORATION OF WISCONSIN.

MOTOR-CONTROLLER.

Specification of Letters Patent.

Patented Apr. 2e, acts,

Application filed November as, 1909. Serial No. 529,909.

' To all whom it may concern .tact, tending Be it known that I, EDWIN B.H. Towns, J r., a citizen'of the United States, residing at Milwaukee,in the county of Milwaukee and State of \Visconsin, have invented newand useful Improvements in Motor-Controllers, of which the following isa full, clear, concise, and exact description, reference being had tothe accompanying drawing, forming a part of this specification.

My invention relates to improvements in controllers for electric motors,and more particularly to controllers including a plurality ofsuccessively operating switches for accelerating the motor.

One of the objects of my invention is to provide means for temporarilychecking the successive operation of the accelerating switches upon theoccurrence ofabnormal conditionsin the motor circuit, or, in otherwords, to prevent the resistance from being removed from circuit toorapidly.

Another object of my invention is to provide each or any desired numberof the ac celerating switches with an auxiliary 0011- to move therewithto cause energization of a succeeding switch and having a controllingwinding for arresting its operation so long as abnormal conditionsprevail in the motor circuit:

A further objectof my invention is to provide means whereby theauxiliary conportion of tact. of each switch, when operated, will remainin the same position, regardless of any subsequent surges of currentthrough. its controlling winding.

Various other objects and advantages ofi my invention will behereinafter clearly and fully set forth.

For the purpose of more clearly disclosing the nature and characteristicfeatures of my invention, I shall describe the embodiment thereofillustrated in the accompany- It should, of course, be understood thatmy invention is notlimited to the particiilar embodiment thereofillustrated, but is capable of various modifications.

The views in the accompa'nying'drawing are as follows:

Figure 1 is a side elevation of a switch embodying certain features of minventicn; Fig. 2 is an enlarged view of tlie upper Fig. 1, showingparts thereof in section; and Fig. 3 diagrammatically illustherethrough.

trates. a system of control employing switches similar to the oneillustrated in Figs. 1 and 2.

The general structure of the switch illus trated' is of conventionalform. Briefly described, this switch comprises a magnet frame 5 securedto a suitable insulating base 6 and having. pivoted thereto a contactarm 7. Mounted within the magnet frame 5 is a solenoid winding 8 havinga plunger 9 connected by a pin 10 to the switch arm 7. The switch arm 7has a main contact 11 and an arcing contact 12 arranged to engagerelatively stationary contacts 13 and 14. The contact 13 comprises alaminated brush rigidly secured to a support 15 which is mounted uponthe front of the magnet-frame and insulated therefrom. The contact 14comprises av carbon block carried by an arm 16 which is-fulcrumed at 17,to the contact support- 15.' The solenoid'winding 8 has a stationarycore 18 with which the plunger is adapted to seal when moved upwardly.-

Secured to the plunger 9 of the solenoid 8 is an upwardly extending tailrod 19, having loosely mounted thereon a contact disk 20. The contactdisk 20 isadapted to bridge contacts 21 and 22 which are mounted uponposts 2-3 secured to and projecting forwardly from the insulating base6. Surrounding the tail rod 19 is a coil 24 which is mounted within amagnet frame 25. The magnet frame may be of any preferred constructionand supported in any suitable manner. As illustrated, the magnet frameis substan- "tially cylindrical and is provided with rearwardlyextending lugs 26 secured to the insulating base 6 to form a supporttherefor. The top 27 of the magnet frame is preferably formed separatefrom the main portion thereof and provided with a cylindrical portion28, projecting into the coil 24. Surrounding the portion 28 is anonmagnetic bushing 29, preferably extending entirely through the coil24;. The portion 28 forms a core for the coil-24, or, in other Words,the top-27, as a whole forms an armature for the coil. therein forpermitting the tail rod 19 to pass The contact disk 20 is mountedon theupper end of the tail rod so to rest upon the top of the magnet frame,and said disk is preferably insulated from 1 both the tail rod andmagnet frame. Upon the upper end of the tail rod is a nut 30 and Thecore 28 has a central aperture surrounding the tail rod between said nutand the contact disk is a coil spring 31. The spring 31 bears againstthe contact disk 20 and acts as a buffer to check the downward movementcf the plunger 9 of the solenoid 8.

' Fixed to the tail rod 19 below the core 28 is a collar 32. Surroundingthe tail rod 19 and interposed between the collar 32 and the core 28 isacoil spring 33. With this arsuiiiciently energizedv to hold its core 28against the pressure of the spring 33, said spring will compress oryield topermit continned operation of the contact arm 7. Thiscompression of the spring 33 results in storing up energy, which willcause the core 28 to be raised as soon as the magnetic pull of thewinding 24 decreases to a predetermined degree. As soon as the magneticpull of the coil decreases to such an extent, the contact disk 20 willbe moved into engagement with contacts 21 and 22. as the top of themagnet frame is raised, air gaps will be inserted in the magnetic pathof the coil 24, thereby further decreasing the magnetic pull of saidcoil. It will, therefore, readily be seen that the coil spring 33 may beso designed. as to predominate the magnetic pulhof the coil 24 uponsubsequent surges of current therethrough, thereby insuring theretention of the armature 27 and contact disk 20 in raised positionuntil the solenoid 8 is deenergized.

I shall now describe the controller diagrammatically illustrated in Fig.3. This controller includes switches 35, 36, 37 and 38 arranged tocontrol an electric motor-'39, having an armature A and a series fieldwinding F. Each of the switches 35, 36 and 3? is of substantially thesame construction as the switch illustrated in Figs. 1 and 2, and theparts thereof will, therefore, be designated by the same referencenumerals. The switch 38 is similar to the remaining switches, exceptthat it is not provided with an auxiliary contact disk. The switches 36,

31'' and 38 are arranged tocontrol resistances It, i and R respectivelyconnected 1n the motor circuit. Nhile I have shown series resistances,it should be understood that par allel resistances might be used ifpreferred.

1 shall now describe the operation of the controller, at the same timeclearly setting forth. the circuit connections therefor, as-- sumingthat current is supplied from main J lines 40 and 41. For initiallycontrolling It will be apparent that the operation of the severalswitches, I have shown a manually operated switch 42 adapted, whenclosed, to complete a circuit circuit which may be traced from main line5 40, through said switch 35, by conductors 45 1 and 46, through theresistances R, R and R in series, by conductor 47 through the conjtrolling coils 24 of the auxiliary contacts of switches 35, 36 and37,-by conductors 48, 49 .and 50, through the Qunotor armature A andseries field winding F to main line 41. The

motor is thus started with all of the resistance in circuit therewith.The coils 24 of the switches 35, 36 and 37 being connected in serieswith the motor, will, of course, vary in strength in accordance with theflow of current to the'motor. Hence, these coils may be so designed asto hold their armatures against the pressure of the springs 33 only whenthere is an abnormal flow of current in the motor circuit. Furthermore,these coils may be adjusted to hold and release their armatures atdifferent current values. Hence, if an abnormal flow of current occursin the motor circuit upon closure of switch 35, the coil 24 thereof willhold its armature 27 and auxiliary contact 20 against the pressure ofthe spring 33 until the flow of current decreases to the predeterminedvalue. Thereupon the spring 33 will over come the magnetism of the coil24 and raise the armature 27, thereby causing the auxiliary contact 20to engage the stationary contacts 21 and 22. Of course, if there is noabnormal surge of current upon closure of the switch 35, the auxiliarycontact 20 thereof will be immediately moved into engagement with thestationary contacts. Upon operation of the auxiliary switch 20, circuitwill be closed from conductor 45 by conductors 51 and 52, through saidauxiliary switch, by conductor 53, through the operating winding ofswitch 36, by conductor 54 to main line 41. Thereupon the switch 36 willrespond.and shortcircuit the resistance B. from the motor circuit.Again, if an excesssive surge of current occurs upon shortcin cuitingthe resistance R, the coil 24 of switch 36 will prevent operation of theauxiliary switch 20 thereof until the flow of current is reduced to thedesired value. Thereupon the auxiliary switch 20 of switch 36 willoperate and close a circuit from conductor 52 to conductor 55, thencethrough the operating winding of switch 37, by conductor 56 to conductorThereupon the switch 37 will respond and shortcircuit resistance R.

Again, if an abnormal surge of current occurs upon shortclrcmtmg theresistance I R,'th'e auxiliary switch 20 of switch 37 will contacts,thereby completinga circuit from conductor 52, by conductor 57, toconductor 58, and thence through the operating winding of switch 38, byconductor 59 to conductor 56. The switch 38 will thereupon respond andshortcircuit resistance R Ihe motor circuit may then be traced from mainline 40,,through switch 35, by conductors 45,

46 and 60, through switch 38, and thence through the motor as alreadytraced. All resistance is thus removed from the motor circuit and themotor will be brought up to normal speed.

As previously set forth, the springs 33 of the several switches may beso designed as to prevent the attraction of any of the armatures 27 bythe coils 24 after they have once been released. Consequently, each oftheaccelerating switches, after having once responded, will beunaffected by any subsequent surges of'current in the motor circuit.

Having thus described my invention, what I desire to secure by LettersPatent, is

1. In a controller for electric motors, in combination, a plurality ofautomatic switches for accelerating the motor, means actuated by saidswitches for causing successive operation thereof, and electroresponshemeans for arresting the operation of said first mentioned means whileabnormal conditions prevail in the motor circuit, said first mentionedmeans being adapted to be arrested independently of the switchesactusting the same.

2. In a controller for electric motors, in

combination, a plurality of automatic switches for accelerating themotor, a plurality of devices, each adapted to be actuated by one ofsaid switches to cause the operation of another switch, andelectroresponsive means for arresting the successive operation of saiddevices'while abnormal conditions prevail in the motor circuit, saiddevices being adapted to be arrested independentlyof the switchesactuating the same.

3. In a controller for electric motors, in

switches for accelerating the motor, a plu rality of devices eachadapted to be actuated by one of said switches to cause the operation ofanother switch, a'resilient connection between each of said devices andits operating switch, and a plurality of controllin windings, one foreach of said devices, eac of said controlling windings being adapted tocheck the operation of its corresponding device while abnormalconditions prevail in the motor circuit.

5. In a controller for electric motors, in combination, a pluralityswitches, a plurality of devices each tendin to operate upon closure ofone of sai switchesto cause the operation of another of said switches, aplurality of controlling windings, one for each of said devices, each ofsaid windings being adapted to arrest operation of its correspondingdevice while abnormal conditions prevail in t-he'motor cir-- cuit, andmeans for retaining each of said devices in the position to which it ismoved regardless of subsequent surges of current through its controllingwinding.

6. In a controller for electric motors, a plurality of electroresponsiveaccelerating switches, a plurality of relay switches each operativelyconnected to one ofsaid accelerating switches and tending to operatetherewith to energize another of said accelerating switches, andelectroresponsive means for arresting the operation of said relayswitches upon the occurrence of abnormal conditions in the motorcircuit, the connection between each relay switch and its correspondingaccelerating switch permitting .operation of the latter, while theformer is arrested and positively operating the former upon restorationof normal conditions.

7. In a motor controller in combination, a plurality ofelectroresponsive accelerating switches, a plurality of relayswitcheseach operatively connected to one of said accelerat-ing switches andtending to operate therewith to energize another of said acceleratingswitches, and electroresponsive means for arresting the operation ofsaid relay switches upon the occurrence of abnormal conditions in themotor circuit independently of their corresponding acceleratingswitches, the connection between eachrelay switch and its'correspondingaccelerating switch insuring operation of the former upon restoration ofnormal conditions, and.

further insuring the retention thereof in the position to which it ismoved regardless of subsequent surges of current 'in the motor circuit.

8. Ina controller for electric motors in combination, a plurality ofelectrores on-' pendently of the former, and a plurality of controllingwindings one for each of said relay switches, each of said windingsbeing adapted to arrest the operation of its corresponding relay switchupon the occurrence of abnormal conditions in the motor circuit.

9. In a controller for electric motors in combination, a plurality ofelectroresponsive accelerating switches, a plurality of relay switches,an operative connection between each of said relay switches and one ofsaid accelerating switches, tending to cause the former to move with thelatter but permitting the latter to move independently of theiformer,and a plurality of controlling windings one for each of said relayswitches, each of said windings being adapted to arrest the operation ofits corresponding relay switch upon the occurrence of abnormalconditions in the motor circuit, the connection between each relayswitch and its corresponding accelerating switch insuring operation ofthe former upon restoration of normal conditions in the motor circuitand further insuring the retention o't its relay switch in the positionto whichit is moved regardless of ,subsequent occurrences of abnormalconditions of the motor circuit.

1.0. In a controller for electric motors, in combination, a plurality ofelectroresponsive accelerating switches, a plurality of relay switches,each having a resilient connection with oneof said accelerating switchesand tending to operate therewith to cause another accelerating switch torespond, and a controlling winding for each of said relay switchesadapted to arrest the operation thereof upon the occurrence of abnormalconditions in the motor circuit.

11. In a controller for electric motors, in

combination a plurality of electroresponsive accelerating switches eachbeing provided with an auxiliary contact adapted to causetheenergization of another accelerating switch, a controlling winding foreach of said auxiliary contacts adapted to prevent operation thereofwhile abnormal conditions prevail in the motor circuit, and resilientconnections between each accelerating switch and its auxiliary contactadapted to have energy stored therein for operating its auxiliarycontact immediately upon restoration of normalconditio-nsin the motorcircuit.

152. In a controller for electric motors, in combination, a plurality ofelectroresponsive accelerating switches, each being provided with anauxiliarycontact adapted to cause the energization of anotheraccelerating switch, a controlling windii'ig for each of said auxiliarycontacts adapted. to prevent operation thereof while abnormal conditionsprevailin the motor circuit, and resilient connections between eachaccelerating switch and its auxiliary contact adapted to have energystored therein for operating its auxiliary contact immediately uponrestoration of normal conditions in the motor circuit, and for' insuringthe retention of its auxiliary switch in the position to which it ismoved, regardless of subsequent surges of current through itscontrolling "winding.

13. The combination with an electric switch, of a device associated withsaid switch, an operative connection between said device and said switchtending to positively actuate said device upon operation of said. switchand electroresponsive means for temporarily checking the operation. ofsaid deviceindependently of said switch.

14. The combination with.- an electric switch, of an auxiliary switch,an operative connection between said switches tending to positivelyoperate the latter upon opera tion of the former, and anelectroresponsive winding for holding said auxiliary switch againstmovementupon operation of said first mentioned switch.

15. The combination with anelectricswitch of an auxiliary switch, aresilient connection between said switches capable of having energystored therein, and an electroresponsive winding for arresting theoperation of said auxiliary switch upon operation of said firstmentioned switch.

16. The combination with an electric switch, of an auxiliary switch, aresilient connection between said switches capable of having energystored therein, an electro responsive winding for arresting theoperation of said auxiliary switch upon operation of said firstmentioned switch, said connec-- tion adapted to insure the retention ofsaid auxiliary switch in the position to which it is moved, regardlessof subsequent energization of said winding.

17. The combination with an electroresponsive switch, of an auxiliarycontact therefor resiliently connected therewith, and an electromagnet{or holding said auxiliary switch stationary upon operation of said.first mentioned switch, said resilient connection being adapted'to haveenergy stored therein'to prevent attraction of said auxiliary switch bysaid magnet after the same has been released.

18. In combination wit-h a power circuit, a plurality of contactorsintended for operation in succession to effect certain connections insaid power circuit, auxiiiary switches cooperating with certain of saidcontactors, each arranged to control the operation of asucceedingcontactor, means for positively holding each auxiliary sw'i.ch open while its cooperating contactor is open, said means permittingeach contactor to close independently of its auxiliary switch, buttending to positively move each aux tions in :said power circuit,'auxiliar-y' switchescooperating with certain of said contactors, eacharranged to control the operation of a succeeding cont actor, amechanical connection between each contactor and its auxiliary switchfor'positively holding the latter open when the former is open, 1:s v

and an electroresponsive controlling winding for each auxiliary switchadapted to holdthe same in open position under predetermined conditions,said connections being arranged to permit closure of each contactorwhile its auxiliary switch is held in open position and to positivelymove the latter to closed posit-ion when released by its controllingwinding. i

20. In a motor controller in combination,

a plurality of electroresponsive acceleratingswitches, auxiliaryswitches associated With certain of said accelerating switches, eacharranged to control the circuit of a succeeding switch, a mechanicalconnection between eachof said switches and its auxiliary switch tendingto positively. close the latter uponclosure of the former, and an eachauxiliary switchfor' preventing closure thereof while abnormalconditions prevail in the motor circuit, said connections being adaptedtopermit closure of each accelerating switch independently of itsauxiliary switch when the latter is held open by its controllingwinding.

In witness whereof, I have hereunto subscribed my name in the presenceof two Witnesses. a

EDWIN B. H. TOWER, JR. Witnesses FRANK H. HUBBARD, S. W. Frrz GERALD.

electroresponsive winding associated with

